Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

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aribert
 
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Default OT repairing Resistance wire heater in Refrigerator

The mullion (part between the refridge and freezer doors, only way that
I know this part's name is that I looked this part up on line) has been
sweating a lot lately and the existing small rust patch has grown much
larger. WHile removing the part to derust and paint it I discovered a
resistance wire heating element under this trim piece. Ohmed it and
confirmed that the wire lacked continuity. By progressively scraping
off tiny patches of insulation along the wire I discovered the failed
area. How do I splice it. The wire is very small in diameter and it
appears to be wrapped around a fabric core, plastic outer insulator.
THere is not enough wire there to twist together. I'm inclinded to
believe that I can not solder the wire. Would I be able to crimp the
wires? What happens locally when there is a discontinuity in the wire
diameter? Will this end up being a hot spot where the wire is inclined
to break again in the near future?


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Jeff Wisnia
 
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Default OT repairing Resistance wire heater in Refrigerator



aribert wrote:

The mullion (part between the refridge and freezer doors, only way that
I know this part's name is that I looked this part up on line) has been
sweating a lot lately and the existing small rust patch has grown much
larger. WHile removing the part to derust and paint it I discovered a
resistance wire heating element under this trim piece. Ohmed it and
confirmed that the wire lacked continuity. By progressively scraping
off tiny patches of insulation along the wire I discovered the failed
area. How do I splice it. The wire is very small in diameter and it
appears to be wrapped around a fabric core, plastic outer insulator.
THere is not enough wire there to twist together. I'm inclinded to
believe that I can not solder the wire. Would I be able to crimp the
wires? What happens locally when there is a discontinuity in the wire
diameter? Will this end up being a hot spot where the wire is inclined
to break again in the near future?


Depending on how hot it gets, you might be able to use silver loaded
conductive epoxy.

I bought some conductive epoxy to fix a broken motor winding (wound with
aluminum magnet wire wouldjabelieve) in our kitchen microwave over 5 years
ago and it's stiil working fine. Been keeping the rest of that epoxy in the
refrigerator freezer compartment and had to use some last year to fix a
disconnected link in a small solar panel. It worked fine for that too.

Jeff


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Eastburn
 
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Default OT repairing Resistance wire heater in Refrigerator

I'd try the silver myself - another source used to be Radio shack -
PCB fix paint - small bottle of silver and clear coat.

Normally heating coils - larger ones anyway - have to be crimp connected
as a solder type connection simply melts.

This one, likely low current and such could be soldered - however in
moisture
it might be the real killer of tin lead. I'd coat with a sealing coat
of
some type.

Martin
--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder
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Jon Elson
 
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Default OT repairing Resistance wire heater in Refrigerator



aribert wrote:

The mullion (part between the refridge and freezer doors, only way
that I know this part's name is that I looked this part up on line)
has been sweating a lot lately and the existing small rust patch has
grown much larger. WHile removing the part to derust and paint it I
discovered a resistance wire heating element under this trim piece.
Ohmed it and confirmed that the wire lacked continuity. By
progressively scraping off tiny patches of insulation along the wire I
discovered the failed area. How do I splice it. The wire is very
small in diameter and it appears to be wrapped around a fabric core,
plastic outer insulator. THere is not enough wire there to twist
together. I'm inclinded to believe that I can not solder the wire.
Would I be able to crimp the wires? What happens locally when there
is a discontinuity in the wire diameter? Will this end up being a hot
spot where the wire is inclined to break again in the near future?


If you can get the replacement heater, that would be the safest thing.
This heater will
be exposed to cold and condensation inside the refrigerator, and you
wouldn't want it
grounding out and zapping somebody or starting a fire.

If you can't get it, or it is outrageously expensive, you could probably
fix it with
some sort of crimped connection. Maybe two crimped butt splices with a
length
of copper wire between to make up the shortage. Then, I'd wrap the
spliced area
with some kind of high temperature insulating tape. The fabric core may
be fiberglass.

If you cut out too much of the resistance element, it is going to run
much hotter
than before, and fail again soon.

I had a similar problem a couple of years ago, where the mullion and the
entire
roof of the refrigerator compartment was sweating all over the food. I
tore it
apart a couple of times, and finally decided I would tear the whole fridge
apart, as it would have to be replaced if I couldn't fix it. It turned
out all the
styrofoam insulation around the frost-free coils, which are enclosed in a
compartment between the refrigerator and freezer comaprtments, were totally
saturated with ice. This thing looks a bit like a small picnic cooler. The
upper sheet is basically a flat piece of styrofoam, and it weighed about
10 Lbs! The bottom part weighed over 25 Lbs! I left them out in the summer
sun for a day, but they weren't getting lighter very fast. So, I put
them in
a garbage bag and hooked up a vacuum pump to drive out the water.
it took several days for each part to clear of the water, but the parts
weighed
just grams when I put them back in. The same frigde is still working fine!

Jon

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Leo Lichtman
 
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Default OT repairing Resistance wire heater in Refrigerator


Jon Elson wrote: (clip) How do I splice it. (clip)
^^^^^^^^^^^^
If the fabric core on which the heater wire is wrapped is still intact, how
about wrapping the area with the break with thin bare copper wire?




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TSJABS
 
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Default OT repairing Resistance wire heater in Refrigerator

If you have a continuous sweating problem I would also look at the seals
around your doors. This will let in moist air and everything will always be
wet.
The defrost elements should be available if you have a "worth fixing" type
refrigerator. My old Kenmore was 17 years old when I bought my house and I
have put on new door gaskets and a defrost timer. Which you should check to
make sure isn't staying on. The defrost timer is probably the #1 item which
goes bad and people simply go buy another refrigerator instead of fixing it.
My defrost timer was under 20 bucks and the local appliance repair center had
one on the shelf.
If I were to place a bet on what happened in your fridge it would be a bad
defrost timer. Your fridge iced up which broke the wire. One simple check you
can make to determine whether an appliance is even worthy of being fixed is to
take an ohm meter and check the cord prongs to the case of the appliance. If
the hot or neutral wire read anything to the case of the appliance it should
really be bye bye time for that item. Compressor motors are bad about high
resistance grounds, they won't trip a breaker but if you get between the case
of the appliance and ground it is more than enough to kill a person.
One other incentive to replace is the efficiency of refridgerators even made
10 or 15 years ago is low enough that a new one will begin to pay for itself
in saved electricity.
In your case any fix that might not properly insulate this wire is like
loading a human mousetrap. If you can't properly fix the defrost element or
can't find a new one its time for a new fridge.

tim
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Kenneth W. Sterling
 
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Default OT repairing Resistance wire heater in Refrigerator

On Fri, 08 Aug 2003 23:38:28 -0400, aribert wrote:

The mullion (part between the refridge and freezer doors, only way that
I know this part's name is that I looked this part up on line) has been
sweating a lot lately and the existing small rust patch has grown much
larger. WHile removing the part to derust and paint it I discovered a
resistance wire heating element under this trim piece. Ohmed it and
confirmed that the wire lacked continuity. By progressively scraping
off tiny patches of insulation along the wire I discovered the failed
area. How do I splice it. The wire is very small in diameter and it
appears to be wrapped around a fabric core, plastic outer insulator.
THere is not enough wire there to twist together. I'm inclinded to
believe that I can not solder the wire. Would I be able to crimp the
wires? What happens locally when there is a discontinuity in the wire
diameter? Will this end up being a hot spot where the wire is inclined
to break again in the near future?


You state that it has a plastic outer insulator - I would go for
soldering, but first slip a little piece of shrink tubing over the
break, then solder (if possible, clean and "hook" the wires together
for mechanical strength), then slide the shrink tubing over the
soldered area and shrink it down.
Ken.

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Stanley Baer
 
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Default OT repairing Resistance wire heater in Refrigerator

I have Tig welded a heater wire in a dryer. The dryer still works and
its been two or three years. I imagine that the wire you are talking
about is thinner though.

stan

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